Parvoviruses are among the smallest DNA-containing viruses that infect animals and man. Parvoviruses range in size from 15 to 28 nm in diameter, lack a lipid membrane (non-enveloped), and contain a single strand of DNA. Parvoviruses are heat stable and generally resistant to chemical deactivating agents, which may account for their prevalence and persistence in the environment. In animals, many diseases such as canine parvovirus and feline panleukopenia exhibit high morbidity and high mortality in affected animal populations and the infections can persist endemically.
The Parvoviridae family is divided into five genera: Parvovirus, Dependovirus, Erythrovirus, Amdovirus and Bocavirus. Animal parvoviruses such as canine parvovirus, feline parvovirus, mink enteritis virus, and porcine parvovirus are responsible for many serious diseases in animals. In humans, the first identified pathogenic member of this family was parvovirus B19, which is a member of genus Erythrovirus. Other B19-related human parvoviruses include A6 and V9. The genomes of A6 and V9 are highly related to that of B19. As with other parvoviruses, B19 is highly contagious and exhibits high morbidity in affected populations. B19 causes fifth disease in normal individuals, transient aplastic crisis in patients with underlying hemolysis, and chronic anemia due to persistent infection in immunocompromised patients. B19 infection in pregnancy can lead to hydrops fetalis and fetal loss. B19 has also been implicated as the cause of chronic arthritis in adults where there is evidence of recent B19 infection, e.g., rheumatoid and inflammatory arthritis.
Parvoviruses are also associated with respiratory tract infections. Lower respiratory tract infections (LRTI) are a leading cause of hospitalization of infants and young children. Animal bocaviruses BPV (bovine parvovirus) and MVC (canine minute virus, or minute virus of canines) are associated with respiratory symptoms and enteritis of young animals. Systemic infection by BPV and MVC appears likely, and there are indications that fetal infection leading to fetal death may occur.
The discovery of a human Bocavirus (HBoV) has been recently reported. (WO2007/057062) HBoV is pathogenic to humans, and is associated with respiratory tract infections in children.
Despite the known pathogenicity of parvoviruses and the urgent need for methods to prevent, diagnose and treat parvovirus infections, other divergent human parvoviruses have not yet been identified. Therefore, a need exists to detect divergent human parvoviruses and to provide a method to diagnose, prevent and treat parvoviruses infection. Moreover, there exists a need to provide methods to identify parvoviruses antiviral compounds.